/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.sound.sampled;

import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;


/**
 * An instance of the <code>AudioFileFormat</code> class describes
 * an audio file, including the file type, the file's length in bytes,
 * the length in sample frames of the audio data contained in the file,
 * and the format of the audio data.
 * <p>
 * The <code>{@link AudioSystem}</code> class includes methods for determining the format
 * of an audio file, obtaining an audio input stream from an audio file, and
 * writing an audio file from an audio input stream.
 *
 * <p>An <code>AudioFileFormat</code> object can
 * include a set of properties. A property is a pair of key and value:
 * the key is of type <code>String</code>, the associated property
 * value is an arbitrary object.
 * Properties specify additional informational
 * meta data (like a author, copyright, or file duration).
 * Properties are optional information, and file reader and file
 * writer implementations are not required to provide or
 * recognize properties.
 *
 * <p>The following table lists some common properties that should
 * be used in implementations:
 *
 * <table border=1>
 * <caption>Audio File Format Properties</caption>
 * <tr>
 * <th>Property key</th>
 * <th>Value type</th>
 * <th>Description</th>
 * </tr>
 * <tr>
 * <td>&quot;duration&quot;</td>
 * <td>{@link java.lang.Long Long}</td>
 * <td>playback duration of the file in microseconds</td>
 * </tr>
 * <tr>
 * <td>&quot;author&quot;</td>
 * <td>{@link java.lang.String String}</td>
 * <td>name of the author of this file</td>
 * </tr>
 * <tr>
 * <td>&quot;title&quot;</td>
 * <td>{@link java.lang.String String}</td>
 * <td>title of this file</td>
 * </tr>
 * <tr>
 * <td>&quot;copyright&quot;</td>
 * <td>{@link java.lang.String String}</td>
 * <td>copyright message</td>
 * </tr>
 * <tr>
 * <td>&quot;date&quot;</td>
 * <td>{@link java.util.Date Date}</td>
 * <td>date of the recording or release</td>
 * </tr>
 * <tr>
 * <td>&quot;comment&quot;</td>
 * <td>{@link java.lang.String String}</td>
 * <td>an arbitrary text</td>
 * </tr>
 * </table>
 *
 * @author David Rivas
 * @author Kara Kytle
 * @author Florian Bomers
 * @see AudioInputStream
 * @since 1.3
 */
public class AudioFileFormat {

  // INSTANCE VARIABLES


  /**
   * File type.
   */
  private Type type;

  /**
   * File length in bytes
   */
  private int byteLength;

  /**
   * Format of the audio data contained in the file.
   */
  private AudioFormat format;

  /**
   * Audio data length in sample frames
   */
  private int frameLength;


  /**
   * The set of properties
   */
  private HashMap<String, Object> properties;


  /**
   * Constructs an audio file format object.
   * This protected constructor is intended for use by providers of file-reading
   * services when returning information about an audio file or about supported audio file
   * formats.
   *
   * @param type the type of the audio file
   * @param byteLength the length of the file in bytes, or <code>AudioSystem.NOT_SPECIFIED</code>
   * @param format the format of the audio data contained in the file
   * @param frameLength the audio data length in sample frames, or <code>AudioSystem.NOT_SPECIFIED</code>
   * @see #getType
   */
  protected AudioFileFormat(Type type, int byteLength, AudioFormat format, int frameLength) {

    this.type = type;
    this.byteLength = byteLength;
    this.format = format;
    this.frameLength = frameLength;
    this.properties = null;
  }


  /**
   * Constructs an audio file format object.
   * This public constructor may be used by applications to describe the
   * properties of a requested audio file.
   *
   * @param type the type of the audio file
   * @param format the format of the audio data contained in the file
   * @param frameLength the audio data length in sample frames, or <code>AudioSystem.NOT_SPECIFIED</code>
   */
  public AudioFileFormat(Type type, AudioFormat format, int frameLength) {

    this(type, AudioSystem.NOT_SPECIFIED, format, frameLength);
  }

  /**
   * Construct an audio file format object with a set of
   * defined properties.
   * This public constructor may be used by applications to describe the
   * properties of a requested audio file. The properties map
   * will be copied to prevent any changes to it.
   *
   * @param type the type of the audio file
   * @param format the format of the audio data contained in the file
   * @param frameLength the audio data length in sample frames, or <code>AudioSystem.NOT_SPECIFIED</code>
   * @param properties a <code>Map&lt;String,Object&gt;</code> object with properties
   * @since 1.5
   */
  public AudioFileFormat(Type type, AudioFormat format,
      int frameLength, Map<String, Object> properties) {
    this(type, AudioSystem.NOT_SPECIFIED, format, frameLength);
    this.properties = new HashMap<String, Object>(properties);
  }


  /**
   * Obtains the audio file type, such as <code>WAVE</code> or <code>AU</code>.
   *
   * @return the audio file type
   * @see Type#WAVE
   * @see Type#AU
   * @see Type#AIFF
   * @see Type#AIFC
   * @see Type#SND
   */
  public Type getType() {
    return type;
  }

  /**
   * Obtains the size in bytes of the entire audio file (not just its audio data).
   *
   * @return the audio file length in bytes
   * @see AudioSystem#NOT_SPECIFIED
   */
  public int getByteLength() {
    return byteLength;
  }

  /**
   * Obtains the format of the audio data contained in the audio file.
   *
   * @return the audio data format
   */
  public AudioFormat getFormat() {
    return format;
  }

  /**
   * Obtains the length of the audio data contained in the file, expressed in sample frames.
   *
   * @return the number of sample frames of audio data in the file
   * @see AudioSystem#NOT_SPECIFIED
   */
  public int getFrameLength() {
    return frameLength;
  }

  /**
   * Obtain an unmodifiable map of properties.
   * The concept of properties is further explained in
   * the {@link AudioFileFormat class description}.
   *
   * @return a <code>Map&lt;String,Object&gt;</code> object containing all properties. If no
   * properties are recognized, an empty map is returned.
   * @see #getProperty(String)
   * @since 1.5
   */
  public Map<String, Object> properties() {
    Map<String, Object> ret;
    if (properties == null) {
      ret = new HashMap<String, Object>(0);
    } else {
      ret = (Map<String, Object>) (properties.clone());
    }
    return (Map<String, Object>) Collections.unmodifiableMap(ret);
  }


  /**
   * Obtain the property value specified by the key.
   * The concept of properties is further explained in
   * the {@link AudioFileFormat class description}.
   *
   * <p>If the specified property is not defined for a
   * particular file format, this method returns
   * <code>null</code>.
   *
   * @param key the key of the desired property
   * @return the value of the property with the specified key, or <code>null</code> if the property
   * does not exist.
   * @see #properties()
   * @since 1.5
   */
  public Object getProperty(String key) {
    if (properties == null) {
      return null;
    }
    return properties.get(key);
  }


  /**
   * Provides a string representation of the file format.
   *
   * @return the file format as a string
   */
  public String toString() {

    StringBuffer buf = new StringBuffer();

    //$$fb2002-11-01: fix for 4672864: AudioFileFormat.toString() throws unexpected NullPointerException
    if (type != null) {
      buf.append(type.toString() + " (." + type.getExtension() + ") file");
    } else {
      buf.append("unknown file format");
    }

    if (byteLength != AudioSystem.NOT_SPECIFIED) {
      buf.append(", byte length: " + byteLength);
    }

    buf.append(", data format: " + format);

    if (frameLength != AudioSystem.NOT_SPECIFIED) {
      buf.append(", frame length: " + frameLength);
    }

    return new String(buf);
  }


  /**
   * An instance of the <code>Type</code> class represents one of the
   * standard types of audio file.  Static instances are provided for the
   * common types.
   */
  public static class Type {

    // FILE FORMAT TYPE DEFINES

    /**
     * Specifies a WAVE file.
     */
    public static final Type WAVE = new Type("WAVE", "wav");

    /**
     * Specifies an AU file.
     */
    public static final Type AU = new Type("AU", "au");

    /**
     * Specifies an AIFF file.
     */
    public static final Type AIFF = new Type("AIFF", "aif");

    /**
     * Specifies an AIFF-C file.
     */
    public static final Type AIFC = new Type("AIFF-C", "aifc");

    /**
     * Specifies a SND file.
     */
    public static final Type SND = new Type("SND", "snd");

    // INSTANCE VARIABLES

    /**
     * File type name.
     */
    private final String name;

    /**
     * File type extension.
     */
    private final String extension;

    // CONSTRUCTOR

    /**
     * Constructs a file type.
     *
     * @param name the string that names the file type
     * @param extension the string that commonly marks the file type without leading dot.
     */
    public Type(String name, String extension) {

      this.name = name;
      this.extension = extension;
    }

    // METHODS

    /**
     * Finalizes the equals method
     */
    public final boolean equals(Object obj) {
      if (toString() == null) {
        return (obj != null) && (obj.toString() == null);
      }
      if (obj instanceof Type) {
        return toString().equals(obj.toString());
      }
      return false;
    }

    /**
     * Finalizes the hashCode method
     */
    public final int hashCode() {
      if (toString() == null) {
        return 0;
      }
      return toString().hashCode();
    }

    /**
     * Provides the file type's name as the <code>String</code> representation
     * of the file type.
     *
     * @return the file type's name
     */
    public final String toString() {
      return name;
    }

    /**
     * Obtains the common file name extension for this file type.
     *
     * @return file type extension
     */
    public String getExtension() {
      return extension;
    }

  } // class Type

} // class AudioFileFormat
